This work is designed to detect and study genes which are associated with transformation in three distinct human population groups which differ genetically in their risk for development of colorectal cancer and their pattern of development of disease. The three groups are: (1)\patients with the autosomal dominant inherited disease, adenomatosis of the colon and rectum (familial polyposis); (2)\patients who have inherited autosomal dominant colon cancer without polyposis; and (3)\patients in the general population with sporadic adenomas, and with primary colon cancer, both postulated to be inherited as a recessive genetic disorder, and which are known to be influenced by environmental factors. Carcinoma, adenoma, and normal biopsy tissue from these three population groups are used as sources of DNA and RNA for two types of experiments. First, DNA transfection experiments with mouse NIH 3T3 cells are used to determine: (a)\if the same or if different transforming genes are associated with colon cancer in each group; (b)\whether transforming gene activity can be detected in adenomas; and (c)\whether the same or different transforming genes can be detected in benign tumors from the different groups. A second approach also is being developed. More than 4,000 cDNA clones of the human colon carcinoma cell line HT-29, which does not have a transforming gene assayable by transfection, have been arrayed in microtiter wells as a primary library. There is a greater than 80% probability that this library contains every abundant and middle-abundant RNA sequence in the tumor line. Replicas of the library will be hybridized to labeled probes from the tissues outlined above, and the resultant X-ray films will be scanned. The result will be a computerized data base of the level of expression of each of the 4,000 cDNA clones in a large number of human colonic biopsy samples, including normal, premalignant, and malignant tissues in the various population groups. Finally, we have generated cell lines from 3T3 cells transformed with human c-rasK, v-rasH. All of these transformed lines form malignant spindle cell tumors in nude mice, but they differ markedly in their morphology and foci formation in culture. Those lines which are morphologically most abnormal show a more pronounced disruption of actin polymerization and a marked decrease in acidic peptides of 32,000 and 33,000 daltons. The question to be investigated is whether the phenotype of the transformed 3T3 cell depends on the individual transforming gene, its site(s) of integration, expression, or upon variables in the recipient cell.